I changed my account from Mojang to Microsoft recently and when I installed the Minecraft Launcher in my new PC, I logged in with my Microsoft account, but it only shows the demo version of Minecraft: Java Edition. However, I bought Minecraft: Java Edition seven years ago.

It points out there is a problem and it cannot connect to Minecraft services. I retried to connect multiple times without any success.

What can I do to solve this error? If there is something I can do...